I. Bailey Sliding T Bevel

I found this in a stack of old tools at a resale store for a $1.00.
It has l. Bailey PATENT MARCH 19TH. 1872 on it in real fine letters.
It is a 8” adjustable sliding T Bevel. It works so much better than my plastic one in my shop.The lever slides and locks in place smoothly and stays tight till you unlock the lever.The body is cast steel with a bronze locking washer. The screw you see is not like a screw if you remove it.It is a clever cam lock style that may very well contribute to how smooth the tool works.